Another free advanced multitrack recording SW "REAPER v.999".http://www.cockos.com/reaper/download-old-0x.php
Newer versions are not free.
For me it seems to be much more advanced than Audacity and Kristal Audio Engine.
It handles most media formats as wav, mp3, midi, etc.
It supports ASIO 2 drivers
VST, DX and DXi plugins are also supported.

The VST handling in Reaper is excellent. Easy to "connect" plug-ins on tracks (pre, and post recording and pre or post fader) and you see the "instrument panel" of the plug-in with all function buttons etc.
And Reaper has a very good "library" function to show all VST(I)and DX(I) plug-ins that it finds on PC harddisk

To get a low track-to-track delay (latency) when recording with KAE and Reaper 0,999 (and most other recording SW) you need an ASIO 2 driver.
ASIO4ALL 2.7 http://www.asio4all.com/ is a free and good driver working with most soundcards.

Reaper's been updated too - Reaper 2. The 0.999 version is still free, version two is unrestricted shareware so you can give it a thorough workout before you splash the minute $50 for non-commercial, $225 for commercial. They're all good, but version 2 really rocks.

Don't spend a lot of money, but I think no should spend their time learning the software that is not use in the industry frequently. If you buy the popular sound cards like DigiDesign and M-Audio, they all come with the software that are worth waisting your time on them.